Locking and release mechanism for a washing machine balancing device



J. F. BELAIEFF 3,356,222 LOCKING AND RELEASE MECHANISM FOR A WASHING MACHINE BALANCING DEVICE Dec. 5, 1967 Filed March 29, 1966 5 Sheets-Sheet .l

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INVENTOR.

JAMES FRANK BELAIEFF AGENT Dec. 5, 1967 J. F. BELAIEFF 3,356,222

LOCKING AND RELEASE MECHANISM FOR A WASHING MACHINE BALANCING DEVICE Filed March 29, 1966 5 Sheets-Sheet 2 FIG.2

INVENTOR. JAMES FRANK BELAIEFF AGEN Dec. 5, 1967 J. F BELAIEF F 3,356,222

LOCKING AND RELEASE MECHANISM FOR A WASHING MACHINE BALANCING DEVICE) Filed March 29, 1966 5 Sheets-Sheet 5 JNVENTOR. JAMES FRANK BELAIEFF 2.1M /e; AGEN United States Patent O 3,356,222 LOCKING AND RELEASE MECHANISM FOR A WASHING MACHINE BALANCING DEVICE James Frank Belaietr, Bellerive, Switzerland, assignor to Frame S.A., Fribourg, Switzerland, a corporation of Switzerland Filed Mar. 29, 1966, Ser. No. 538,304 Claims priority, application Switzerland, Apr. 20, 1965, 5,475/ 65 7 Claims. (Cl. 210-363) ABSTRACT OF THE DISCLOSURE A locking mechanism for retaining eccentrically mounted balancing masses in a fixed position with respect to the drive shaft on a rotating drum washing machine. The balancing masses are aligned by the locking mechanism so that the center of gravity of the masses lies along the axis of the drive shaft until the rotating drum attains a predetermined critical speed at which time the masses are released in order to perform their balancing function.

The invention relates to clothes washing and centrifuging machines, of the type comprising a drum rotating about a non-vertical axis and provided with a balancing device comprising two water-tight chambers arranged symmetrically with respect to the transverse plane of symmetry of the basket and concentrically with respect to its axis of revolution and which are rigidly secured to the drum, each chamber being partly filled with a liquid and containing at least two eccentric masses which are journalled on the driving shaft of the basket so as to be freely rotatable.

A known clothes washing machine of this type comprises at least one balancing member which is constituted by at least two masses which are freely movable in an oil-filled chamber. During washing the masses are inoperative because the oil circulation produced by the rotary movement of the chamber is insufficient to drive the masses.

At the high speeds of revolution, and in particular that for centrifuging, the masses are driven by the oil until their speed is equal to that of the chamber.

Only when the relative speed of the masses and the chamber is Zero and the speed of the basket has surpassed the critical speed can the masses take their suitable places with respect to the unbalance produced by the washing in the drum.

During said driving period of the masses, said masses move in the direction of the unbalance produced by the washing and as a result cause the suspended assembly to produce irregular oscillations of large amplitude.

On the other hand, the known machine is normally constructed with two balancing members arranged on either side of the drum in which synchronization of the driving of the masses between each balancing member cannot be achieved. A displacement of a few degrees of the position of the masses is sufficient to produce disturbing moments on the shaft of the drum which produce irregular movements in the suspended assembly. These disturbances can be avoided with difiiculty only by providing shock absorbers or inertia masses which are provided on the tub as a result of which the forces on the bearings which support the basket are considerably increased and sometimes the centre of gravity of the assembly is displaced with respect to the shaft of the drum.

The invention is characterized in that each chamber includes a locking device which, when the drum is rotated at a speed lower than its critical speed, determines the position of the eccentric masses relative to one another in such manner that the centre of gravity of the assembly of said masses becomes located on the axis of revolution of the drum and, when the drum is driven at a speed higher than its critical speed, releases the eccentric masses under the influence of the centrifugal force, the masses then taking a suitable position for compensating for the unbalance of the drum.

In order that the invention may readily be carried into effect, it will now be described in greater detail with reference to the accompanying drawings which show diagrammatically a clothes washing and centrifuging machine with two variations of the balancing device for the washing and centrifuging drum, in which:

FIGURE 1 shows a side elevation in partial cross-section of a washing machine which includes a balancing device;

FIGURE 2 is a plan view partly in cross-section of the machine shown in FIGURE 1;

FIGURE 3 is a side elevational view in partial crosssection of a water-tight chamber of a first embodiment of the balancing device;

FIGURE 4 is a cross-section of FIGURE 3;

. FIGURE 5 is a side elevational view in partial cross section of a water-tight chamber of a second embodiment of the balancing device; and

FIGURE 6 is a cross-section of FIGURE 5.

Although the drawings and the specification relate to a clothes washing and centrifuging machine for domestic use, that is to say having a capacity of from 2 to 7 kgs. of dry washing, the invention is equally readily applicable to industrial machines for washing, centrifuging and drying washing.

The machine shown comprises a rotating drum 1 comprising a horizontal driving shaft 2 which coincides with its axis of revolution, the ends of the said shaft rotating in bearings 3 provided outside the tub 4 of the machine. Flexible connections 5 ensure the tightness of the tub 4 at the point where the shaft 2 is passed through the Walls. The tub 4 is rigidly secured to the frame 6 of the machine, 'while the drum is suspended with respect to the frame 6, that is to say it is connected to the frame 6 through tension springs 7 and shock absorbers 8 and it can thus move in three orthogonal directions.

At its upper side the tub 4 has an aperture which can be closed by means of a lid 9 pivotably secured to the frame 6 of the machine. On its periphery 11, the basket 1 comprises a lid 10 for putting the washing into the drum and removing it again.

The balancing device comprises two equal chambers 12 arranged on either side of the rotating drum. Each of the chambers 12 is water-tight and is constituted by a lid 13 which is rigidly secured to the side wall 14 of the drum 1. This chamber 12 is arranged concentrically to the driving shaft 2 of the drum. The ends 15 of the driving shaft 2 rotate in bearings 3 which are mechanically secured to the frame 6 of the washing machine.

Each water-tight chamber 12 is constituted by a bottom which is either formed directly by the side wall 14 of the drum or, more generally, by a strengthening member 18 which is secured to the side wall 14 and by a lid 13 which is rigidly secured to the bottom in such a manner that a water-tight chamber 12 is formed.

Inside each of the Water-tight chambers 12 which are partly filled with oil, two masses 16 are arranged, each comprising a radial arm 19 which is journalled on the driving shaft 2 of the drum. In the embodiment shown each mass has the shape of a semicircular segment, the diameter of which is smaller (of the order of 0.5 to 2 cms. than the inside diameter of the chamber 12. The thickness of the masses 16 is less than half the thickness of the chamber 12 and the masses rotate beside one another on the driving shaft 2.

Each chamber 12 comprises a device for locking the eccentric masses 16 in position located diametrically opposite to one another as shown-in FIGURE 3. With this locking device the masses 1-6 can be fixed relativeto the chamber 12 in such positions that the centre of gravity of the assembly of the said two-masses 16 becomes located on the driving shaft 2. When these masses are thus locked, they increase the inertia of the drum 1", but remain inoperative as regards the balancing hereof.

In the first embodiment shown in FIGURES 3' and 4, the locking device is constituted by cams 20 bolted to a leaf spring 21 which is secured to the peripheral wall of the chamber 12. Each mass 16 is held in its position by two cams 20 located diametrically opposite to one another the front faces 22 of which each contact a face 23 of the corresponding mass 16. This face 23 of the mass 16 comprises two lugs 35 for fixing the radial position of the cams 20 in the locked position of the masses 16.

In the embodiment shown the leaf springs 21 are integral with a circular tape 24 which engages the inner surface of the chamber 12 in a flexible manner so as to be taken along in the direction of rotation of the chamber by the frictional force.

When during washing the drum 1 rotates at a speedlower than its critical speed, the centrifugal force onthe cams 29 in general is insufficient to displace-them radially against the elastic force of the leafspring 21. In this manner the masses 16 are locked and taken along synchronously with the chamber-12 by the circular tape 24.

On the contrary, the force of the leaf springs 21 and the mass of the cams 20 are determined; such that, when the drum exceeds the critical speed, the centrifugal force on each of the said bolts is sufficient to move them radially in the direction of the peripheral wall of the chamber 12 against the flexible action of the leaf springs 21, so that said cams 20 are released from the faces 23 of the masses 16. These masses which are still driven by the oil which partly. fills the chamber arereleased and then assume such a position as to compensate for the unbalance of the basket.

To balance the basket, the masses 16 perform only a restricted angular movement which at any rate is less than 180. This is very important for, on the one hand the balancing of the vessel or basket iselfected substantially immediately after releasing the masses 1 6 and, on the other hand, the phenomenon ofthe oscillations of great amplitude produced by the progressive drive of the balancing masses in the known devices, is fully avoided.

In addition, the increase of theinertia of the-basket 1, due to the masses 16, greatly decreases the oscillations produced by the unbalance of the washing, when the drum passes through thecriticalspeed.

It is to be noted that during the decrease of the speed of the drum the masses 16 may temporarily have a larger speed than the drum, so that, when the locking members again take the position shown in FIGURE 1 as a result of the action of thes-prings 21, themasses 16 violently abut the said locking members. However, the circular tape 24 is not rigidly secured to the peripheral wall but elastically engages the said wall, said tape will slide along the said wall as a result of the violent impact. From this it follows that the circular tape 24 which is also rotated as a result of the friction constitutes a shockabsorber against the. sudden impacts of the locking member during locking the masses 16.

Consequently, the above-described balancing device provides an important technical advance with respect to the known washing machines. For a more detailed explanation of the operation of the masses 16, reference may be had to U.S. Patent 3,178,916, issued Apr. 20, 1965.

In the second embodiment shown in FIGURES and 6, the locking members are not secured to the chamber 12, but to the masses 13. Each mass 16 includesa cavity, opening into one of the surfaces and into the periphery and which provides communication with a blind hole 26. A locking member 27 arranged in the cavity is pivotal relative to the mass 16 around the pin 28. The locking member includes an inertia mass 29 on one side, a cam lock 30 on the other side. The cam surface 31 is biased by a tension spring 32 arrangedin the blind hole 26'. In this manner the locking member 27 is held in the position shown in FIGURE 5, and a catch 33 for the cam 30 contacts a cam receiving plate 34, secured to-the circular tape 24 which is elastically secured to the peripheral wall of the water-tight chamber 12; The plate 34 includes a recess 36 for receiving the catch 33 of the cam 31).

In the position shown in FIGURE 5, the mass 16 is locked with respect to the chamber 12, and is rotated synchronously by said chamber as long as the centrifugal force of the inertia mass 29 is insufficient to overcome the force of the spring 32-. The characteristics of thespring and the proportions of the locking member 27 are such-that as a result of the centrifugal force the locking member 27 is displaced through an angle in the direction of the arrow 1 as a result of which the mass 16 is released'when the rotary speed of the basket 1 exceeds its critical speed.

In principle, the operation of this second embodiment is the same as that of the first embodiment. During washing and gaining speed of the basket for centrifuging the washing, the balancing masses 16 are held in positions located diametrically opposite to one another in such manner that they no longer influence the unbalance ofthe drum but on the contrary increase the inertia of the drum. Ifthen the critical speed of the basket is exceeded; the masses 16 are released and take such a position that they compensate for the unbalance of the basket.

The chambers 12 are partly filled with a viscous oil, for example, an oil which can drive the balancing masses.

Numerous variations may be provided, for example, in which the number of balancing means 16 differs from two'and is, for example, three.

In, an embodiment not shown the position of the balancing masses of the same chamber could be fixed withrespect to one another by means of the same-locking device, in which the assembly of the two masses, however, could rotate freely on the shaft 2. In such acase one locking device may be provided which secures the two masses 16 together, but nevertheless it is useful in general to provide a second locking device which mechanically secures the assembly of the masses, or each mass individually, to the chamber 12 to obtain a greater acceleration of the balancing masses during acceleration of the drum from washing speed to centrifuging speed. As a result of the centrifugal force, the locking device releases the as sembly of the said masses preferably just before the locking: device disengages the masses 16 from one another.

What, is claimed'is:

1. In a rotating drum, washing and centrifuging machine having" a balancing device for said rotating drum including a plurality of rotatable eccentric masses journalled on the drive shaft of said rotating drum and rotatable in an, annular path therewith, the improvement comprising: lockingmeans operative at speeds of said shaft less than a predetermined critical speed for securing said eccentric massesat predetermined positions around said drive shaft andilocating the center of'gravity of said masses along the axis. of, said drive shaft; and centrifugal force release means for disengaging said eccentric masses when said drumrotates at said critical speed.

2. In a rotating drum washing and centrifuging machine according to claim 1, the improvement further comprising: means for damping the impact produced when saidmasses engage said locking means.

3. In a rotating drum washing and centrifuging ma, chineaccording to claim 2 wherein said locking means comprises a pivotal locking member mounted on each of said rotatable eccentric masses, a tape attached to said rotatable drum and concentricaly surrounding said path of movement of said rotatable eccentric masses, said tape having a catch thereon for receiving said locking member, and biasing means forcing said locking member into engagement with said catch; and said centrifugal force release means comprises an inertial weight attached to said pivotal locking member for counteracting said biasing means when said rotating drum attains said critical speed thereby releasing said locking member from said catch.

4. In a rotating drum washing and centrifuging machine according to claim 1, wherein said locking means comprises a tape engaging said rotatable drum and rotating therewith, said tape being positioned outside and concentric to the annular path of movement of said rotatable eccentric masses and a radially movable cam means attached to said tape for engaging said rotatable eccentric masses; and said centrifugal force release means comprises a spring means interconnecting said cam means and said tape, said spring means applying a biasing force to said cam means for lockingly engaging said cam means with said rotatable eccentric masses, said biasing force being counteracted by the centrifugal force created by said drum rotating at said critical speed thereby releasing said eccentric masses from said locking engagement with said cam means.

5. In a rotating drum washing and centrifuging machine according to claim 4 wherein: said eccentric masses comprise a pair of semicircular segments rotatably mounted in axial spaced relation on said drive shaft, said axis of said drive shaft passing through the geometric center of the circle which defines said semicircle; said tape is annularly shaped and concentrically surrounds the circular face of said semicircular segments; said cam means comprises two pair of cam elements, each of said pairs of cam elements being axially spaced on said drive shaft, with each of said cam elements of said pair being in diametrically opposed relationship and engaging one of the radial faces of each of said semicircular segments for holding said radial faces of each of said semicircular segments in parallel alignment; and said spring means comprises four leaf springs, each of said leaf springs biasingly interconnecting one of said cam elements with said annular tape.

6. In a rotating drum and centrifuging machine according to claim 5, wherein said annular tape frictionally engages said rotating drum for damping the impacts produced when said semicircular segments are coupled by said cam elements.

7. In a rotating drum washing and centrifuging machine according to claim 1 wherein said locking means comprises a pivotal locking member mounted on each of said rotatable eccentric masses, a tape attached to said rotatable drum and concentrically surrounding said path of movement of said rotatable eccentric masses, said tape having a catch thereon for receiving said locking member, and biasing means forcing said locking member into engagement with said catch; and said centrifugal force release means comprises an inertial weight attached to said pivotal locking member for counteracting said biasing means when said rotating drum attains said critical speed thereby releasing said locking member from said catch.

References Cited UNITED STATES PATENTS 4/1965 Belaieff et al. 210-363 X 

1. IN A ROTATING WASHING AND CENTRIFUGING MACHINE HAVING A BALANCING DEVICE FOR SAID ROTATING DRUM INCLUDING A PLURALITY OF ROTATABLE ECCENTRIC MASSES JOURNALLLED ON THE DRIVE SHAFT OF SAID ROTATING DRUM AND ROTATABLE IN AN ANNULAR PATH THEREWITH, THE IMPROVEMENT COMPRISING: LOCKING MEANS OPERATIVE AT SPEEDS OF SAID SHAFT LESS THAN A PREDETERMINED CRITICAL SPEED FOR SECURING SAID ECCENTRIC MASSES AT PREDETERMINED POSITIONS AROUND SAID DRIVE SHAFT AND LOCATING THE CENTER OF GRAVITY OF SAID MASSES ALONG THE AXIS OF SAID DRIVE SHAFT; AND CENTRIFUGAL FORCE RELEASE MEANS FOR DISENGAGING SAID ECCENTRIC MASSES WHEN SAID DRUM ROTATES AT SAID CRITICAL SPEED. 